Gibbons & Williams issued 30 Shilling, £1, £3, £5, and £10 notes. Their notes were among the more attractive of the period, also being printed on both sides. 30 Shilling £1and £3 notes were payable in Dublin only, with £5 and £10 notes being payable in London also.

The bank failed in 1835.

Denominations: 30/-, £1, £3, £5, £10.
As far as I know, there are no denominations higher than £10 known.

Thirty Shilling notes & Three Pound notes were both among the most common denominations issued by Irish banks up to 1844, when 30 shilling notes were prohibited. £3 notes continued to be issued up to 1915.

Good question. It is entirely possible that there are two types of £3 and £5 note. The Type 1 £1 and 30 Shilling notes are dated 1st July 1833. If there are £3 and £5 notes of this date, they may have a design different to that of the later dates. It would be interesting to see if anyone has a £3 or £5 dated 1st July 1833 so we could check this out.

We'll have to have a look through the past sales of notes for a £3 and £5 dated 1 July 1833 and see. There have been a few of these notes turning up in sales. I have a scan of another £5 notes, must haul it out and see what date it is...

EDIT: Found it!
Here is a £5 note dated 1st July 1833. A definite pattern in emerging here, but only in the dates used. this £5 note is the same design as the one above, with the later date of 1st Sept 1833.

Interesting to see that the 1st July 1833 £5 note has a similar design to the later dates. This strongly suggests that there is only one type for the £5 notes. Given the low issue numbers for the £10 notes, there is most likely only one type for the £10 notes also (No.99 is the highest number I have seen, see attached). However, it would still be interesting to see a £3 note dated 1st July 1833 to confirm if there is just one type for this denomination also.

Had another look at the £5 notes. There appears to be a difference between the note dated 1st July 1833 and the later dates. The 'Five Pounds' centre and top right is hollow for the early date but shaded for the later dates.

I am still hopeful that there is a second £3 note type It would be interesting to see a £3 note dated 1st July 1833. The earliest date I have seen so far is 1st Sept. 1833. A second £10 type is possible if a date later than 1st July 1833 was issued.

Here is an interesting Gibbons & Williams fiver.
It appears to have 'Johnstown' written across the signature panel—I have no idea what meaning that could have.
This is also the highest serial number I have seen for the £5 denomination.